Telephone communication system over a single telephone line

ABSTRACT

A module and kit for coupling at least one telephone service signal to at least one telephone device over a wiring. The network includes: a wiring having at least two conductors for carrying multiple time-domain multiplexed digitized voice channels; an exchange side device coupled to the wiring and operative to couple at least one telephone service signal to at least one digitized voice channel; and at least one subscriber side device coupled to the wiring and operative to couple the at least one telephone device to at least one digitized voice channel.

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation of application Ser. No. 09/594,765, filed on Jun.16, 2000 now U.S. Pat. No. 7,106,721, the disclosure of which isincorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to the field of telephony communicationnetworks, and, more specifically, to the networking of telephone setswithin a building over single telephone line.

BACKGROUND OF THE INVENTION

There is a growing need for expanded telephone communicationcapabilities within the home. This need is driven by two major factors:the increasing use of additional outside lines and the desirability ofexchange functionality within the home, such as for intercom systems.

Telephone Wiring

An in-home telephone service usually employs two or four wires, and isaccessed via telephone outlets into which the telephone sets areconnected. FIG. 1 shows the wiring configuration of a prior-arttelephone system 10 for a residence or other building, wired with aresidential telephone line 5. The residential telephone line 5 consistsof single wire pair which connects to a junction-box 16, which in turnconnects to a Public Switched Telephone Network (PSTN) 18 via a cable 17a, terminating in a public switch 19, which establishes and enablestelephony from one telephone to another. The term “analog telephony” asused herein denotes traditional analog low-frequency audio voice signalstypically under 3 KHz, sometimes referred to as “POTS” (“Plain OldTelephone Service”), whereas the term “telephony” in general denotes anykind of telephone service, including digital service such as IntegratedServices Digital Network (ISDN). The term “high-frequency” as usedherein denotes any frequency substantially above such analog telephonyaudio frequencies, such as that used for data. ISDN typically usesfrequencies not exceeding 100 KHz (typically the energy is concentratedaround 40 KHz). The term “telephone line” as used herein denoteselectrically-conducting lines which are intended primarily for thecarrying and distribution of analog telephony, and includes, but is notlimited to, such electrically-conducting lines which may be pre-existingwithin a building and which may currently provide analog telephonyservice. The term “telephone device” as used herein denotes, withoutlimitation, any apparatus for telephony (including both analog telephonyand ISDN), as well as any device using telephony signals, such as fax,voice-modem, and so forth.

Junction box 16 is used to separate the in-home circuitry from the PSTNand is used as a test facility for troubleshooting as well as for wiringnew in the home. A plurality of telephones 13 a and 13 b connects totelephone line 5 via a plurality of telephone outlets 11 a, 11 b, 11 c,and 11 d. Each outlet has a connector (often referred to as a “jack”),denoted in FIG. 1 as 12 a, 12 b, 12 c, and 12 d, respectively. In NorthAmerica, RJ-11 is commonly used. Each outlet may be connected to atelephone unit via a connector (often referred to as a “plug”), denotedin FIG. 1 (for the two telephone units 13 a and 13 b illustrated) as 14a and 14 b, respectively. It is also important to note that lines 5 a, 5b, 5 c, 5 d, and 5 e are electrically different segments of the samepaired conductors.

While network 10 exhibits serial or daisy-chained topology wherein thewiring is serialized from an outlet to the next one only, othertopologies such as star, tree or any arbitrary topology may also beused. The telephone wiring system within a residence, however, is alwayscomposed of wired media: two or four copper wires, and outlets whichprovide direct access for connecting to these wires.

Additional Subscriber Lines

FIG. 2 illustrates a telephone network 20 in a home, where an additionalsubscriber line 17 b is required to be added to existing line 17 a.Additional line 17 b comes from exchange 18 to home junction-box 16. Inorder to provide access to additional line 17 b, a new outlet 11 e mustbe installed. In addition, a new telephone line 6 a must be installed,routed from junction box 16 to the outlet 11 e. In such an installation,a telephone set 13 c is connected using a cable 15 c, via connectors 14c and 12 e to the added subscriber line.

Alternatively, the new wiring 6 a can be routed together and as part ofexisting wiring 5, using the same in-wall routing. In such a case,either several new telephone outlets need to be installed, or theexisting outlets need to be replaced with ones employing two or moretelephone connectors.

In both the cases described above, new wiring must be added. The routingand installation of such wiring is both labor-intensive and expensive.Adding the new wiring on the exterior of the wall is less expensive, butmay be aesthetically undesirable.

In buildings where four wires (two pairs) have been installed, adding asecond subscriber line is quick and easy. The second pair of theexisting wiring is used for the second subscriber line, thus obviatingthe need for routing additional wires. However, the same problem ofneeding additional wires is encountered in this case when a third orfourth subscriber line is required. In general, additional wiring isrequired whenever adding a new subscriber line to a home exceeds thecapacity of the existing wiring.

FIG. 2 illustrates the case where the added subscriber lines involve theuse of dedicated wiring from the exchange to the home for each suchadded subscriber line. New technology, however, enables multiple voicechannels to be carried over a single twisted-pair (local-loop),Specifically, Digital Subscriber Line (DSL) technologies are available.For example, ISDN-BRA (Integrated Services Digital Network—Basic RateAccess, commonly referred to as ISDN) can carry two voice channels overa single twisted pair, HDSL (High Bit rate Digital Subscriber Line)supports up to 16 voice channels, and HDSL2 supports up to 30 voicechannel over a single twisted pair. These and other such technologiescommonly employ two modems, connected to each end of the twisted pair,as shown in network 30 in FIG. 3. The pair 17 in the local loopinterfaces in the exchange side with an exchange terminal unit 32, whichcommunicates over the local loop pair to a remote terminal unit 31,located at the customer side of the cable. Remote terminal unit 31 inturn provides subscriber line interfaces 17 a and 17 b, connected tojunction box 16. In an alternate configuration, the voice channels aremultiplexed within a digital stream, such as PCM highway, ATM or otherbuses.

The recent move towards de-regulation has enabled the subscriber toreceive telephone services from providers other than the traditionaltelephone companies. One example is the competitive carriers in theUnited-States. In addition, non-telephone businesses, such as cabletelevision and satellite-based network providers, are starting to offertelephone services. Thus, the customer may select added subscriber linesto be supplied by different service providers. FIG. 4 illustrates aconfiguration for such a customer, employing a telephone network 40. Afirst telephone line is supplied by a traditional telephone company asshown in FIG. 1 and previously described. However, a second telephoneline is provided by a non-original telephone provider, which connects tonon-telephone network 41. For example, this can be a cable televisionnetwork. The voice channel is provided via a remote terminal unit 42,which provides the additional telephone line 6 a, and communicates withthe non-telephone network 41. For example, the remote terminal unit 42can be part of Set-Top Box or Cable Modem.

Exchange Features

As used herein, the phrase “PABX-type features”, or the idiomaticequivalent thereof, is intended to encompass features including, but notlimited to: hold/call pick up; call transfer between subsets; conferencecalls; calls coming from, or going to, a central office exchange;ringing on all subsets; repertory dialing; memory dialing. A rapidexpansion in residential-oriented telephone systems and equipment hasbeen developing to satisfy an ever growing number of needs related totelephone communication. One particular need in many residences is theability to selectively communicate among a number of telephone sets allof which are connected via the single central office telephone line thataccesses the residence. In addition, other identified needs ofresidential subscribers are similar to those of businesses having aprivate automatic branch exchange (PABX). However, most such existingexchanges require ‘star’ topology, in which all outlets are directlyconnected to the exchange. While this topology is supported in someresidences, most buildings do not employ such a topology, as the examplein FIG. 1 illustrates. In such a case, a private automatic branchexchange cannot easily be employed, unless effort is made to modify thewiring into ‘star’ topology. U.S. Pat. Nos. 4,821,319, 4,459,434,5,090,052, 5,596,631, 5,781,622 and 6,038,300, as well as other patentsclassified under US Classes 379/177 and 379/363, disclose a fewembodiments enabling limited exchange functionalities in a residenceusing single wire pair.

Data over Telephone Lines

There is a requirement for simultaneously using the existing telephoneinfrastructure for both telephone and data networking. In this way, thetask of establishing a new local area network in a home or otherbuilding is simplified, because there would be no additional wires toinstall. U.S. Pat. No. 4,766,402 to Crane (hereinafter referred to as“Crane”) teaches a way to form a LAN over two-wire telephone lines, butwithout the telephone service.

The concept of frequency domain/division multiplexing (FDM) iswell-known in the art, and provides means of splitting the bandwidthcarried by a wire into a low-frequency band capable of carrying ananalog telephony signal and a high-frequency band capable of carryingdata communication or other signals. Such a mechanism is described, forexample, in U.S. Pat. No. 4,785,448 to Reichert et al (hereinafterreferred to as “Reichert”). Also widely used are xDSL systems, primarilyAsymmetric Digital Subscriber Loop (ADSL) systems.

As another example, relevant prior-art in this field is disclosed inU.S. Pat. No. 5,896,443 to Dichter (hereinafter referred to as“Dichter”). Dichter suggests a method and apparatus for applyingfrequency domain/division multiplexing (FDM) technique for residentialtelephone wiring, enabling simultaneously carrying telephone and datacommunication signals. The bandwidth enabled by the wiring is split intoa low-frequency band capable of carrying an analog telephony signal anda high-frequency band capable of carrying data communication signals. Insuch a mechanism, the telephone service is not affected, while datacommunication capability is provided over existing telephone wiringwithin a home.

The Dichter network is illustrated in FIG. 5, which shows a network 50serving both telephones and providing a local area network of dataunits. Data Terminal Equipment (DTE) units 24 a, 24 b, and 24 c areconnected to the local area network via Data Communication Equipment(DCE) units 23 a, 23 b, and 23 c, respectively. Examples of DataCommunication Equipment include modems, line drivers, line receivers,and transceivers (the term “transceiver” as used herein denotes acombined transmitter and receiver). DCE units 23 a, 23 b, and 23 c arerespectively connected to high pass filters (HPF) 22 a, 22 b, and 22 c.The HPF's allow the DCE units access to the high-frequency band carriedby telephone-line 5. In a first embodiment (not shown in FIG. 5),telephones 13 a, 13 b, and 13 c are directly connected to telephone line5 via connectors 14 a, 14 b, and 14 c, respectively. However, in orderto avoid interference to the data network caused by the telephones, in asecond embodiment (shown in FIG. 5) low pass filters (LPF's) 21 a, 21 b,and 21 c are added to telephones 13 a, 13 b, and 13 c from telephoneline 5. Furthermore, a low pass filter may also be connected to JunctionBox 16, in order to filter noises induced from or to the PSTN wiring 17.It is important to note that lines 5 a, 5 b, 5 c, 5 d, and 5 e areelectrically different segments of the same paired conductors.

Additional prior-art patents in this field can be found under US Class379/093.08, which relates to carrying data over telephone wiring withoutany modifications made to the telephone wiring (e.g. wires and outlets),U.S. Pat. No. 5,841,360 and U.S. patent application Ser. Nos. 09/123,486and 09/357,379 to the present inventor are the first to suggestmodifying the telephone wiring, by means of splitting the wiring intodistinct segments, each of which connects two telephone outlets. In thisway, the network is modified from ‘bus’ topology into multiple‘point-to-point’ segments, enabling superior conmunicationcharacteristics.

Part of such a network 60 is shown in FIG. 6, describing outlets 31 aand 31 b, substituting outlets 11 of FIG. 1. The telephone wiring 5 issplit into distinct segments 5 a, 5 b, and 5 c. Low-Pass Filters (LPF)and High-Pass Filters (HPF) are coupled to each wire segment end, inorder to split between the telephony and the data signals. As shown inFIG. 6, LPF's 21 b and 21 c are respectively attached to opposite endsof the wiring segment 5 b. The LPF's are designed to allow passing ofthe telephony signals, and are connected together thus offering acontinuous path for the telephony signals. Access to the telephonysignals is made via connectors 12 a and 12 b in the outlets, into whichtelephone devices 13 a and 13 b are connected via connectors 14 a and 14b respectively. Thus, the telephony service is fully retained. The datasignals, carried in the high part of the spectrum, are accessed viaHPF's 22 b and 22 c, also coupled respectively to opposite ends of thetelephone wire segment 5 b. HPF's 22 a and 22 d are connected to theends of the wire segments 5 a and 5 c respectively. Each HPF isconnected to a modem 23, which transmits and receives data signals overthe telephone wiring. Modems 23 a, 23 b, 23 c, and 23 d are connected toHPF's 22 a, 22 b, 22 c and 22 d respectively. Data units 24 a and 24 bare connected to the outlets 31 a and 31 b respectively, via arespective connector (not shown in the Figure) in each outlet. The dataunits are coupled via a respective DTE interface in the outlet. Outlets31 a and 31 b comprise DTE interfaces 29 a and 29 b respectively. Thethree data streams in each outlet, two from each modem and one from theDTE, are handled by an adapter 28 a and an adapter 28 b, which serveoutlets 31 a and 31 b, respectively. While FIG. 6 describes anembodiment wherein all the components for the relevant functions arehoused within the outlet, other embodiments are also possible, whereinonly some of the components for these functions are contained within theoutlet.

Life-Line

The term “life-line” as used herein denotes the basic use of thetelephone service for emergency purposes. As such, it is required that amalfunction of any other system or service (e.g. electricity) will notdegrade the telephone system capability. In practical terms, this meansthat as long as an operational telephone set is connected to theexchange via continuous two wires, the telephone service will bemaintained, even in the case of power outage.

There is thus a widely recognized need for, and it would be highlyadvantageous to have, a means for implementing a telephone systemin-home, wherein the telephone units can be networked within the home aswell as to multiple external subscriber lines, without requiring theinstallation of additional wires within the home. This goal is met bythe present invention.

SUMMARY OF THE INVENTION

The present invention, discloses an improved telephone system within abuilding over a single telephone line. The telephone line with thebuilding is used as a medium for a communication network carryingmultiple voice channels in a TDM (Time Domain multiplexing) fashion. Newwiring or a pre-existing telephone lines may be used. In each outlet,conversion between one or more of the data voice channels to and from astandard analog telephone signal (POTS) is performed by a module. Theexchange features previously described are implemented by digitallyrouting the voice channels between the outlets. Signals from externaltelephone feeders (connections between the telephone service provider'scentral office and the line within the building) can also be digitizedby a module and routed within the communication network. In this way,standard analog telephone equipment and signals therefrom can beinterfaced by the modules and used in a multiple voice channel networkover a single telephone line.

Two types of communication network are supported. In the firstconfiguration, the telephone wiring is retained in the typicalcontinuous arrangement, thereby forming a bus-type network where themodule within each outlet has a single telephone-line modem. In thesecond configuration, the telephone lines are broken at each outlet, anda telephone-line modem is coupled to each wire end, thereby formingpoint-to-point communication segments between each pair of connectedoutlets.

The module that couples the telephone line to the telephone interface,or any of the components of the module, can be fully integrated into theoutlet, partially integrated into the outlet, or externally configured.

Life-line functionality is facilitated by using passive filters toseparate the available line bandwidth into a low band and a high band.The high band is used by the multiple voice channel communicationnetwork, while the low band is used for carrying a standard analogtelephone service without using any active components. In such a case,each outlet may contain a life-line telephone interface and one or moretelephone interfaces for the voice channels carried by the communicationnetwork.

Therefore, the present invention provides for use with a telephoneinstallation within a building, the telephone installation having a lineand external connections between the line and a central office of atelephone service provider, a system for connecting to the telephoneinstallation so as to allow more voice channels to be carried over theline without requiring modification or extension of the telephoneinstallation, the system comprising at least two modules for coupling tothe telephone line, wherein said modules are operative for:

(i) converting between at least one standard analog telephone signal andat least one time-domain multiplexed voice channel; and

(ii) interfacing with standard analog telephone equipment and signalstherefrom.

Furthermore, according to the present invention there is provided a kitfor upgrading a pre-existing telephone installation having a line withina building so as to allow more voice channels to be carried over theline without requiring modification or extension of the telephoneinstallation, the kit including:

(i) at least one outlet, said outlet having a connection for coupling tothe line; and

(ii) a module operative for:

a) converting between at least one standard analog telephone signal andat least one time-domain multiplexed voice channel; and

b) interfacing with standard analog telephone equipment and signalstherefrom.

Moreover, according to the present invention there is provided a methodfor upgrading a pre-existing telephone installation having a line withina building, so as to allow more voice channels to be carried over theline without requiring modification or extension of the telephoneinstallation, the method including the steps of:

(i) providing a telephone line modem;

(ii) providing a subscriber-line interface;

(iii) providing a drop-and-insert multiplexer for interfacing betweenthe voice channels and said subscriber-line interface;

(iv) providing an outlet; and

(v) equipping said outlet with said telephone-line modem, saidsubscriber-line interface, and said drop-and-insert multiplexer.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is herein described, by way of example only, withreference to the accompanying drawings, wherein:

FIG. 1 shows a common prior art telephone line wiring configuration fora residence or other building.

FIG. 2 shows a prior art two-line telephone wiring configuration for aresidence or other building.

FIG. 3 shows a first prior-art telephone network for providing multiplelines to a residence or other building.

FIG. 4 shows a second prior-art telephone network for providing multiplelines to a residence or other building.

FIG. 5 shows a first prior-art local area network based on telephoneline wiring for a residence or other building.

FIG. 6 shows part of a second prior-art local area network based ontelephone line wiring for a residence or other building.

FIG. 7 shows a module according to a first embodiment of the presentinvention.

FIG. 8 shows a telephone network according to the first embodiment ofpresent invention,

FIG. 9 shows a module according to the first embodiment of the presentinvention, which supports life-line capability.

FIG. 10 shows a telephone network according to the first embodiment ofpresent invention, which also support life-line capability.

FIG. 11 shows a module according to a second embodiment of the presentinvention, which supports life-line capability.

FIG. 12 shows a telephone network according to the second embodiment ofpresent inventions which also supports life-line capability.

FIG. 13 shows a kit for upgrading an existing telephone installation tosupport a system according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The principles and operation of a network according to the presentinvention may be understood with reference to the drawings and theaccompanying description. The drawings and descriptions are conceptualonly. In actual practice, a single component can implement one or morefunctions; alternatively, each function can be implemented by aplurality of components and circuits. In the drawings and descriptions,identical reference numerals indicate those components which are commonto different embodiments or configurations.

A fist embodiment of the present invention is based on an adapter module(hereinafter denoted as a “module”), which enables the connection of astandard telephone set to the data communication network over thetelephone line. FIG. 7 illustrates the functionality of a module 70.Module 70 has two ports: one for connecting to the telephone line andthe other for connecting to one or more telephone sets. The moduleinterfaces the data communication network over the telephone line by atelephone line modem 23, which can use DCE 23 a as in Dichter network 50(FIG. 5). The data communication network carries multiple digitized(e.g. PCM) voice channels. A drop-and-insert multiplexer 71 installs andexacts voice channels to and from the digital data stream in the datacommunication network. The voice channels to be handled by module 70 aremanaged by a logic, control and PBX unit 73. Each voice channel isconverted into single telephone (POTS) interface via a subscriber lineinterface 72 a, which converts the digital voice channel stream into ananalog interface, capable of connecting to a standard telephone set viaa connector 12. In order to facilitate a second telephone to beconnected to the module 70, an additional subscriber line interface 72 bis added, and couples to multiplexer 71 and to the logic, control andPBX unit 73. Subscriber line interface 72 b handles an additionaldistinct voice channel. An additional telephone set can connect tosubscriber line interface 72 b via a connector 15. While the module 70is described as having two-line support via connectors 12 and 15, tosubscriber line interfaces 72 a and 72 b respectively, the samearrangement also applies to a single-line interface, from whichsubscriber line interface 72 b and connector 15 are omitted. It is alsoclear that module 70 can support more than two such interfaces, whereeach such additional such interface requires an additional subscriberline and connector, as well as a respective support by drop-and-insertmultiplexer 71.

Module 70 may also contain additional logic, control, processing, datastorage, and a power-supply. Except for facilities such as logic,control, and PBX capabilities, which are handled by unit 73, suchadditional functions are performed by other components not shown in FIG.7.

A first embodiment of a network of the present invention is based on theDichter network. FIG. 8 illustrates a network 80, and is based uponmodules, such as module 70 (FIG. 7), where each module allows a singletelephone set to interface via connector 12. Each such module 70 isfully housed and integrated within a telephone outlet, such as outlets88 a, 88 b, 88 c, and 88 d, where telephone line modem 23 connects tothe telephone line port of the outlet, and the telephone connectorconnects to the telephone set.

As shown in FIG. 8, a data communication network is formed such that thetelephone line modem (as telephone line modem 23) within each outlet(such as outlets 88 a, 88 b, 88 c, and 88 d) allows networking betweenand among the outlets, using telephone line 5 a, 5 b, 5 c, 5 d, and 5 eas the network media. Thus, telephones 13 a and 13 b can communicatebetween network. In order to facilitate connection to external telephonenetworks, a module 85 must be added. Module 85 bridges the externaltelephone lines to the in-home data communication network over thetelephone line. Network 80 interfaces to two external telephone linesvia wire pairs 86 a and 86 b, which can be part of a PSTN network asshown in FIG. 2, or from other outside sources as previously described.External lines 86 a and 86 b are converted to digital streams byexchange line interfaces 81 a and 81 b respectively. The voice channelsare coupled to a drop-and-insert multiplexer 82, which inserts into orextracts from the digital multiplexed data stream. The multiplexed datastream is coupled to a telephone line modem 83, which communicates via acable 84 with the in-home data network.

While network 80 has been described having two external feeders 86 a and86 b, it is clear that a single such feeder can also be used. Forexample, if only line 86 a is used, exchange line interface 81 b isunnecessary. Alternatively, more than two such external feeders can beused. For each additional feeder, an additional exchange line interfacemust be furnished, along with additional support capability of thedrop-and-insert multiplexer 82.

Implementing the network 80 within a residence requires replacingtelephone outlets, such as outlet 11 a (FIG. 1) by outlets according tothe present invention, such as outlet 88 a (FIG. 8), each containing amodule, such as module 70 (FIG. 7). In this case, the line segments 5 a,5 b, 5 c, 5 d and 5 e each correspond to the single twisted pair shownin FIG. 7 connected to the telephone line modem, and the outlets 88 a,88 b, 88 c and 88 d are connected to the line segments using a bustopology. In addition, a module such as nodule 85 must also be installednear the junction box 16. However, no new lines within the building needbe installed or routed. After installing the network 80 within aresidence, both the exchange features and the capability to interfacetwo or more external telephone lines are available.

Both module 70 and module 85 contain active components. Thus, in theevent of a power loss or malfunction in any of the components, thenetwork 80 may fail to provide telephony service. In order to support‘life-line’ capability, therefore, the module requires additionalcomponents. FIG. 9 illustrates a modified module 90 that provideslife-line capability. A High-Pass Filter (HPF) 22 and a Low-Pass Filter(LPF) 21 split the telephone spectrum into a low band for carryingstandard analog signals, and into a high band for the data communicationnetwork, as described by Dichter. LPF 21 uses only passive components,and is directly coupled to a connector 91. Hence, a telephone setplugged into the connector 91 can provide ‘life-line’ functionality,without any active components involved in the signal path. Module 90 mayfeature only the life-line connector 91, or may have the life-lineconnector 91 in addition to the connectors 12 and 15. Alternatively, inother embodiments of the present invention, modules may not employ‘life-line’ connection 91 at all.

FIG. 10 illustrates a network 100 according to the first embodiment ofthe invention, and features a modified network supporting life-linefunctionality. Network 100 includes modules 90 a, 90 b, 90 c, and 90 d,integrated within outlets 105 a, 105 b, 105 c, and 105 d respectively.Here, too, the line segments 5 a, 5 b, 5 c, 5 d and 5 e each correspondto the single twisted pair shown in FIG. 9 connected to the junction ofthe low pass filter 21 and the high pass filter 22, and the outlets 105a, 105 b, 105 c and 105 d are connected to the line segments using a bustopology. Outlets 105 a, 105 c, and 105 d have connectors 12 a, 12 c and12 d respectively, which support telephony interfaces based on voicesignals carried by the data communication network. However, outlet 105 balso has a connector 91, which provides the life-line connection asshown in FIG. 9. The low band of the spectrum carries POTS signals fromtelephone line 17, connected to the in-home network via HPF 21. Hence,telephone set 13 b is directly connected to line 17, thereby offeringlife-line service. The high band of the spectrum is used for the datacommunication network, and connects externally via HPF 22. Both LPF 21and HPF 22 are connected by a cable 102 to junction box 16. Allcomponents serving the external line interface are included in module101. In another embodiment of the present invention, each outlet (suchas outlets 105 a, 105 b, 105 c, and 105 d) provides both life-lineinterface 91 in addition to at least one telephone interface 12, suchthat life-line access is available in all outlets within the residence.

While FIG. 10 illustrates the case where the module 90 is fullyintegrated within the outlet 105, embodiments of the present inventionalso include those where the module is external to the outlet. Likewise,selected components of a module may be integrated within the outletwhile other components remain external. In all cases, of course, theappropriate electrical and mechanical connection between the module andthe outlet are required.

An outlet according to the invention is physically similar in size,shape, and overall appearance to a standard outlet, so that such anoutlet can be substituted for a standard outlet in the building wall. Nochanges are required in the overall telephone line layout orconfiguration.

While the invention has been so far described wherein the datacommunication network is based on the Dichter topology, the presentinvention can equally-well be applied to the prior-art wired networktopology illustrated in FIG. 6, which is based on point-to-point datacommunication between any pair of connected outlets. FIG. 11 illustratesa module 110 supporting such a network, along with the life-linefeature. The general configuration is similar to the module 90 describedin FIG. 9. However, the connection to each telephone line segment of thepoint-to-point configuration has a high-pass filter (such as an HPF 22 aand an HPF 22 b) a low-pass filter (such as an LPF 21 a and an LPF 21b), and a dedicated telephone line modem (such as modem 23 a and modem23 b). A drop-and-insert multiplexer 111 inserts the voice channelsinto, and extracts the voice channels from, both data streams handled bytelephone line modems 23 a and 23 b. However, voice channels not used bythe module should be routed to other modules. In the case where threeline segments are connected, an additional such set is required. The twoLPF's 21 a and 21 b provide direct access to the lower band of thespectrum, and are jointly connected to life-line connector 91. Iflife-line support is not required, filters 21 a, 21 b, 22 a, and 22 b,as well as connector 91 can be omitted. Logic, control, PBX and othercomponents such as power supply are not shown in FIG. 11. Additionalcapabilities may be provided by such components to manage such tasks asdata handling and protocol conversions.

FIG. 12 illustrates a network 120 utilizing the modules 110. Each outletsuch as outlet 115 a, 115 b, 115 c, and 115 d, contains a module such asmodule 110 (FIG. 11). In this case, however, the line segment 5 acorresponds to the twisted pair shown in FIG. 11 connected to thejunction of the low pass filter 21 a and the high pass filter 22 a,whilst the line segment 5 b corresponds to the twisted pair shown inFIG. 11 connected to the junction of the low pass filter 21 b and thehigh pass filter 22 b. In like manner, the line segments (5 b, 5 c), (5c, 5 d), and (5 d, 5 e) each connected to the outlets 115 b, 115 c and115 d correspond to a respective twisted pair connected respectively tothe junction of the low pass filter 21 a and the high pass filter 22 aand to the junction of the low pass filter 21 b and the high pass filter22 b in FIG. 11. In general, the network structure of network 100 (FIG.10) is retained. However, in this configuration, the outlets 115 a, 115b, 115 c and 115 d are connected to the line segments using apoint-to-point (or daisy chain) topology.

Upgrade Kit

The present invention also provides for a kit for upgrading an existingtelephone installation to support a network as described herein. FIG. 13illustrates an embodiment of such a kit containing an outlet 132 and anoutlet 134 and installation instructions 136. Outlet 132 has aconnection 144 for coupling to a telephone line and mounting points suchas a flange 146 for installing in the building walls. Outlet 132 alsohas a jack 138 and a jack 140. The first supports life-line telephoneservice via connector 91 (FIG. 9) while the latter provides telephoneservice with improved exchange features. Within outlet 132 is a moduleaccording to the present invention, as previously described andillustrated in FIG. 9 or FIG. 11. Likewise, in an embodiment of thepresent invention, jack 138 is a telephone jack. In another embodiment,jack 140 is a data jack. The embodiment of the kit illustrated in FIG.13 has two outlets, outlet 132 and outlet 134, which are illustrated assubstantially identical. However, in another embodiment, the kitcontains only outlet 132. Other variations are also possible indifferent embodiments. As with the modules described previously,additional components and capabilities may be provided to manage suchtasks as data handling and protocol conversions.

The present invention also provides a method for upgrading apre-existing telephone installation having a line within a building, tosupport a network as described herein. The method involves:

(i) providing a telephone line modem;

(ii) providing a subscriber-line interface;

(iii) providing a drop-and-insert multiplexer for interfacing betweenthe voice channels and said subscriber-line interface;

(iv) providing an outlet; and

(v) equipping said outlet with said telephone-line modem, saidsubscriber-line interface, and said drop-and-insert multiplexer.

In another embodiment of the present invention, the existinginstallation can be upgraded to support life-line communication. In sucha case, there are the additional steps of:

(vi) providing passive high-pass and low-pass filters for separating alower band for standard analog telephone service from a higher band formultiplexed voice channels;

(vii) connecting the filters to isolate the standard analog telephoneservice from the multiplexed voice channels; and

(viii) providing a connector to connect a standard telephone set to thestandard analog telephone service.

While the invention has been described with respect to a limited numberof embodiments, it will be appreciated that many variations,modifications and other applications of the invention may be made,

Thus, for example, whilst the invention has been described withparticular reference to a network installed in a domestic residence, itwill be apparent that no such limitation is intended and the inventionis equally well applicable for use in non-domestic premises such asoffice, factories and the like.

1. A device for coupling a telephone device to at least one time-domainmultiplexed digitized voice channel carried over bus topology wiring ina building, the wiring having at least two conductors, the devicecomprising: a local area network modem couplable to the wiring andoperative to communicate with at least one other modem over the bustopology wiring in the building; selective means coupled to said localarea network modem and operative to pass a first voice channel; asubscriber line interface coupled to said selective means and operativeto convert said first voice channel to a first analog telephone signal;and a first telephone connector coupled to said subscriber lineinterface and couplable to a telephone device to couple the telephonedevice to said first analog telephone signal.
 2. The device according toclaim 1, wherein the wiring is existing wiring in walls of the buildingand said device is operative to communicate with another device that isinterchangeable with said device in the building over the wiring.
 3. Thedevice according to claim 2, wherein the wiring is connected toconcurrently carry a service signal.
 4. The device according to claim 3,wherein the wiring is a telephone wiring.
 5. The device according toclaim 2, wherein the device is dimensioned to be mountable in an outletcavity in a wall.
 6. The device according to claim 2, wherein the deviceis at least in part housed within an outlet.
 7. The device according toclaim 1 wherein the wiring is connected to concurrently carry afrequency domain multiplexed second analog telephone signal in atelephone band, and the device further comprises: a frequency selectivemeans couplable to the wiring and operative to pass the said secondanalog telephone signal; and a second telephone connector coupled tosaid frequency selective means for coupling a telephone device to saidsecond analog telephone signal.
 8. The device according to claim 1,wherein the multiplexed digitized voice channels carry Pulse CodeModulation (PCM) signals.
 9. The device according to claim 1, whereinthe wiring is connected to further carry data signals, and the devicefurther comprises a data connector operative to couple the data signalsto a data unit.
 10. A kit for use with a wiring system in a buildinghaving a continuous wire pair and multiple outlets for connecting tosaid wire pair and forming a bus topology, the wire pair carrying atleast one time-domain multiplexed digitized voice channel, said kitcomprising: at least two devices, each as defined in claim 1, all ofsaid devices having modems, and each of said modems being operative tocommunicate with all other modems of the other devices.
 11. The deviceaccording to claim 1, further comprising means for detachablyelectrically and mechanically coupling said device to an outlet openingin a wall.
 12. A device for coupling at least one analog telephoneservice signal to at least one time-domain multiplexed digitized voicechannel carried over a wiring having at least two conductors, for usewith an analog telephone service connection for conducting the analogtelephone service signal and connectable to an analog telephone set, thedevice comprising: at least one exchange line interface connectable tothe at least one analog telephone service connection, and operative toconvert the at least one analog telephone service signal to a digitizedservice signal; and a modem coupled to said at least one exchange lineinterface and operative to conduct said digitized service signal overthe wiring.
 13. The device according to claim 12, wherein the device isused for coupling multiple service signals to multiple time-domainmultiplexed digitized voice channels carried over the wiring, andwherein the device further comprising selective means coupled to saidmodem and to said at least one exchange line interface and operative toselectively couple said multiple digitized voice channels carried overthe wiring to said digitized service channels.
 14. The device accordingto claim 12, wherein the wiring is existing wiring in the building, andsaid modem is operative to communicate with modems in the building overthe existing wiring.
 15. The device according to claim 14, wherein thewiring is connected to concurrently carry a service signal.
 16. Thedevice according to claim 15, wherein the wiring is a telephone wiring.17. The device according to claim 14, wherein the device is dimensionedto be mountable in an outlet cavity in a wall.
 18. The device accordingto claim 14, wherein the device is at least in part housed within anoutlet.
 19. The device according to claim 12, wherein the wiring isconnected to concurrently carry a frequency domain multiplexed analogtelephone signal in a telephone band, and the device further comprises:a connection means for coupling to an analog telephone service; and afrequency selective means coupled to said connection means and couplableto the wiring, and operative to pass the analog telephone signal. 20.The device according to claim 12, wherein the multiplexed digitizedvoice channels carry Pulse Code Modulation (PCM) signals.
 21. The deviceaccording to claim 12, wherein the wiring is connected to further carrydata signals, and the device further comprises a data connectoroperative to couple the data signals to a data unit.
 22. The deviceaccording to claim 12, wherein said modem is operative to communicatewith at least one other modem over the wiring.